Synergistic utilization of TiO ₂ -photo-generated holes and electrons is a potential protocol for catalytic C–C bond formation reactions.

A sensitive nano-device for D-glucose detection is prepared by modifying a single conical polymer nanochannel with GOx enzymes. The current–voltage (I–V) characterization suggests that the nano-device responds to D-glucose rather than its enantiomer at concentrations down to 1 nM (10⁻⁹ mol L⁻¹). Moreover, the nano-device exhibits good reproducibility and specificity for D-glucose and is an ideal candidate for commercial non-invasive blood glucose meters in the future.

Covalent organic frameworks (COFs) are defined as highly porous and crystalline polymers, constructed and connected via covalent bonds, extending in two- or three-dimension. Compared with other porous materials such as zeolite and active carbon, the versatile and alternative constituent elements, chemical bonding types and characteristics of ordered skeleton and pore, enable the rising large family of COFs more available to diverse applications including gas separation and storage, optoelectronics, proton conduction, energy storage and in particular, catalysis. As the representative candidate of next-generation catalysis materials, because of their large surface area, accessible and size-tunable open nano-pores, COFs materials are suitable for incorporating external useful active ingredients such as ligands, complexes, even metal nanoparticles deposition and substrate diffusion. These advantages make it capable to catalyze a variety of useful organic reactions such as important C-C bond formations. By appropriate pore-engineering in COFs materials, even enantioselective asymmetric C-C bond formations could be realized with excellent yield and ee value in much shorter reaction time compared with their monomer and oligomer analogues. This review will mainly introduce and discuss the paragon examples of COFs materials for application in C-C bond formation reactions for the organic synthetic purpose.

Two dendritic organic–inorganic hybrid nanomaterials with eight silole units covalently bonded to a POSS core were prepared via a one-step hydrosilylation reaction. These hybrid nanomaterials exhibited aggregation-enhanced emission phenomenon, and displayed outstanding thermal stability and high fluorescence quantum yield. The emissions of these nanoaggregates were selectively quenched by 2,4,6-trinitrophenol. The high selectivity of the sensors was attributed to the combined effects of electron and energy transfer processes. These novel hybrid nanomaterials have the potential to prepare sensitive, selective, and stable sensors for the detection of explosives in aqueous media.

Fulfilling the direct inert C–H bond functionalization of raw materials that are earth-abundant and commercially available for the synthesis of diverse targeted organic compounds is very desirable and its implementation would mean a great reduction of the synthetic steps required for substrate prefunctionalization such as halogenation, borylation, and metalation. Successful C–H bond functionalization mainly resorts to homogeneous transition-metal catalysis, albeit sometimes suffering from poor catalyst reusability, nontrivial separation, and severe biotoxicity. TiO₂ photocatalysis displays multifaceted advantages, such as strong oxidizing ability, high chemical stability and photostability, excellent reusability, and low biotoxicity. The chemical reactions started and delivered by TiO₂ photocatalysts are well known to be widely used in photocatalytic water-splitting, organic pollutant degradation, and dye-sensitized solar cells. Recently, TiO₂ photocatalysis has been demonstrated to possess the unanticipated ability to trigger the transformation of inert C–H bonds for C–C, C–N, C–O, and C–X bond formation under ultraviolet light, sunlight, and even visible-light irradiation at room temperature. A few important organic products, traditionally synthesized in harsh reaction conditions and with specially functionalized group substrates, are continuously reported to be realized by TiO₂ photocatalysis with simple starting materials under very mild conditions. This prominent advantage—the capability of utilizing cheap and readily available compounds for highly selective synthesis without prefunctionalized reactants such as organic halides, boronates, silanes, etc.—is attributed to the overwhelmingly powerful photo-induced hole reactivity of TiO₂ photocatalysis, which does not require an elevated reaction temperature as in conventional transition-metal catalysis. Such a reaction mechanism, under typically mild conditions, is apparently different from traditional transition-metal catalysis and beyond our insights into the driving forces that transform the C–H bond for C–C bond coupling reactions. This review gives a summary of the recent progress of TiO₂ photocatalytic C–H bond activation for C–C coupling reactions and discusses some model examples, especially under visible-light irradiation.